WASHINGTON, Sept 9 (AFP) - The Pentagon is investigating up to 100 "ghost detainees" who were held in secret custody by US forces in Iraq, the army general probing the Abu Ghraib prison abuse scandal told a congressional committee Thursday.
General Paul Kern told the Senate Armed Service Committee that investigators "found many reports -- of which we cannot document for you because the documentation does not exist -- of people that were brought into the facilities and who were moved so that they could not be identified by the International Red Cross."
"This is in violation of our policy which requires us to register people so that it can be reported that they are being held in detention," he said.
Kern said that the Pentagon has commissioned two probes -- by the Department of Defense inspector general and the CIA inspector general -- into the illegal practice, which he described as "perhaps one of the more troubling pieces of our investigation."
Earlier, the team of investigators had estimated that US forces hid some eight ghost detainees from the International Committee of the Red Cross, in clear violation of the Geneva Conventions.
Human Rights Watch decried the hidden imprisonments.
"Secret detention is the gateway to torture," said Reed Brody, the legal counsel for the New York-based group. "History shows that when people are taken off the books, that is when they are most vulnerable to all kinds of abuse, including mistreatment, torture and even disappearance."
Kern made his remarks as the Armed Services Committee heard testimony into the abuse scandal.
As of mid-August, 66 allegations of abuse have been substantiated, Pentagon officials told the panel at a hearing to give lawmakers details about findings of the Defense Department probe.
The prison abuse scandal emerged in April after several now-notorious photographs depicting the abuse at Abu Ghraib were made public.
The photos showed Iraqi inmates on leashes, held naked, piled in a human pyramid, or hooded and attached to electrodes. None of those prisoners were being held for interrogation, an army official said.
The chairman of the Senate committee, Republican Senator John Warner of Virginia, said at the hearing that more than 300 allegations of abuse of prisoners in Iraq and Afghanistan have been made to date.